Car rental companies have been contemplating offering high-end luxury cars recently, for those who want to convey a lifestyle or cachet with their vehicles.

Hertz launched the Prestige Collection in the U.S. in 2001, allowing clients the opportunity to choose from a selection of higher-end vehicles, such as Mercedes and BMWs.

Last year, Hertz decided to step it up, adding much higher end vehicles to their roster, such as the Ferrari F430 Spider, Lamborghini Gallardo and Bentley Continental GT. These vehicles all have retail costs that are six figures.

These ultra high-end vehicles are part of Hertz's Supercars, a program that launched an online-booking platform last year. It was introduced in the U.S., U.K., France, Italy, Spain and the Netherlands. The program does not have a large collection, as the income level that would demand it is relatively small, with fewer than 200 cars on offer in total.

Hertz began adding ultra luxury cars to its luxury cars in 2011, when it added the Lotus Evora to its collections in 15 locations, mainly in airports, in Germany, Spain and the U.K.

"We wanted to gauge the appetite for luxury car hire," Zoe White, a Hertz spokesman, told CNN. When the launch was an overwhelming success, Hertz added more to the collection.

Enterprise Rent-a-Car ran a similar business model experiment in the U.S. in 2005, when they launched their Exotic Car Collection in West Los Angeles. It included Aston Martins and Bentley convertibles. In a city that is all about image, the program was extremely successful. 

Enterprise has now expanded the program to 13 additional locations across six states, with cars prominently displayed at the Los Angeles International Airport, where some customers choose to upgrade their vehicle on the spot.

"We have local customers who want to add a special touch to a big event, out-of-towners who want to enjoy their vacation in style and business travelers who use the cars to entertain big clients," said Steve Short, the vice president of leisure business development for Enterprise.

Avis has gotten in on this aspect of the business as well.

"We found that people want to rent a luxury car in order to give the impression they are doing well for themselves," said Kay Ceille, the managing director at AvisBudget U.K. "They want to stand out from the crowd and be taken more seriously."

Ceille thinks that the recession is the best time to focus on luxury vehicle rentals, because in tough times, luxury rentals have increased in popularity.

Through market research, AvisBudget found that their U.K. customer base was renting vehicles from the Prestige Collection and Select Series, their vehicle fleets comprising BMWs and Jaguars, for the purpose of impressing someone else for both personal and professional reasons. They found, for example, that more than a quarter of the customers surveyed chose to upgrade before a job interview.

"For customers who want a taste of the millionaire lifestyle, it's value for money," said White, adding these rentals often come with perks, such as a chauffeur or airport meet-and-greet service.

These ultra luxury vehicles are still very pricey. A Mercedes SLK Sport can cost more than $200 per day and a McLaren MP4-12C can cost around $1,300. 

It's still much cheaper than buying one.